Understanding Browser Processes, TCP/IP, and HTTP: Common Interview Questions

The article begins by emphasizing that mastering browser internals and network protocols such as TCP/IP and HTTP can solve most front‑end challenges and boost career development.

Question 1: Chrome opens a page using four processes – a browser (main) process, a GPU process, a network process, and a renderer process – to improve stability, performance, and security, while increasing resource consumption.

Question 2: TCP guarantees complete delivery of page resources through sequence numbers, acknowledgments (ACK), retransmission, and three‑way handshake (SYN, SYN‑ACK, ACK). The article describes packet structure, TCB, and contrasts TCP’s reliable, connection‑oriented nature with UDP’s connectionless, faster but unreliable behavior.

Question 3: HTTP, built on TCP, handles client‑server communication. The article outlines DNS resolution, port selection, request construction, caching, connection reuse (keep‑alive), and the differences between HTTP/1.0, 1.1, and 2, including pipelining, multiplexing, and server push. It also explains status codes 301 and 302 and why subsequent page loads are faster due to DNS and resource caching.

Question 4: The end‑to‑end flow from URL input to page display includes domain name resolution, TCP connection establishment, HTTP request/response exchange, possible redirects, and finally rendering in the renderer process after resource parsing.

The article concludes by encouraging readers to use this knowledge for interview preparation and to consider what points to assess when asking candidates about the URL‑to‑page rendering process.